/PROBE_TIMER=n

    Optional. Default: 75 seconds.

    Number of seconds between probes for idle TCP connections (when
    the SO_KEEPALIVE option is set). If the remote system fails to
    respond, the connection is removed. Also, when initiating a TCP
    connection request, indicates the maximum number of seconds that
    the software waits for a response from the remote system before
    the request times out.